Cardinal Keith O'Brien, who has defended the Scottish government's decision to release the Lockerbie bomber. Photograph: David Moir/Reuters

This week, Cardinal Keith O'Brien reiterated his objection to the death penalty, a position that I admire and support. However, in order to make headlines, he chose a path of cynicism and hubris. O'Brien twisted the facts around the compassionate release of the Lockerbie bomber to support his platform and criticised anyone who objects as perpetuating a "culture of vengeance".

I would argue that many "objectors" are fighting for justice, which often requires more courage, faith and conviction than simply showing compassion.

O'Brien began with St Paul's words about "vengeance is mine, says the Lord". But this does not remove the moral responsibility to hold individuals accountable for their actions and protect the innocent. As we learn in St Luke's gospel: "If your brother sins, rebuke him, and if he repents, forgive him."

Abdelbaset al-Megrahi and his sponsor, Muammar Gaddafi, are unrepentant murderers. By sending the mass murderer back to the same country that ordered the attack, we legitimise and elevate that regime.

O'Brien goes on about the death penalty in the US, but completely negates the value of the lives of millions of Libyans Scotland has betrayed by releasing al-Megrahi and enabling Gadaffi's oppression. Freedom House ranks Libya as one of the seven worst nations in the world with respect to human freedom. And Gadaffi himself admits that 20% of Libya's 6 million people live in abject poverty, even though he controls $60bn in annual oil revenue. This is not just about the victims of the Lockerbie bombing.

Then, O'Brien glosses over the point that the release decision was based on "due process and clear medical evidence". We now know that not one oncologist or urologist would give the required "three months to live" diagnosis. The only doctor to agree to that diagnosis was a general practitioner who was a subcontractor to the Scottish prison system. And dozens of prisoners die of natural causes every year in Scottish prisons. Why was al-Megrahi considered a special case?

Well, O'Brien failed to mention that, two months before the release, the Scottish National party received a visit from the Qatar Investment Authority (QIA), a Middle East-based sovereign wealth fund critical to SNP's plans for capital investment and greater economic independence from the UK. The QIA made it clear that "it would not be helpful if Megrahi dies in prison." Clearly, the vaunted Scottish justice system had been corrupted by the political needs of the SNP.

As we read in Deuteronomy, "Those who show mercy to the wicked will bring cruelty to the world." I would argue that terrorists around the world see weakness and corruption in this move, not compassion. We embolden terrorists when we are too cowardly to uphold our own judgments. How is it right that al-Megrahi served only 11 days for murdering a little child four days before Christmas in Lockerbie?

For years, I have prayed over the issue of vengeance v justice. I often thought it would be easier simply to "forgive and forget", and that is what many people want.

However, I think justice – in and of itself – is worthy of relentless pursuit. We never asked for al-Megrahi to be put to death. We simply begged that we not sell his release for political expediency. In fact, we strongly advocated that he should receive the best palliative care possible in Scotland.

I resent and condemn Cardinal O'Brien's characterisation of a supposed US "culture of vengeance" – purely because we have the courage to hold people responsible in this instance. Unfortunately, it is not the first time the leaders of the Catholic church have landed on the wrong side of history and righteousness. I only hope my fellow Catholics in Scotland will see through the hypocrisy.